sedimentary
Jasper
Silicon dioxide (SiO2) with impurities
AI-generated identification · may be incorrectHardness: 6.5-7 (Mohs), Color: Reddish-brown and mustard-green, Luster: Vitreous to dull, Crystal structure: Microcrystalline/Cryptocrystalline, Specific Gravity: 2.58-2.91
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs), Color: Reddish-brown and mustard-green, Luster: Vitreous to dull, Crystal structure: Microcrystalline/Cryptocrystalline, Specific Gravity: 2.58-2.91
Formation & geological history
Formed in hydrothermal environments or as sedimentary deposits where silica-rich fluids permeate through volcanic ash or sediment, carrying iron oxides that provide color.
Uses & applications
Used primarily for lapidary work, jewelry (cabochons), ornamental decorations, and as a popular collector's stone due to its varied patterns.
Geological facts
Jasper is an opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning 'spotted stone'. It was a favorite gemstone in the ancient world, mentioned in many historical texts.
Field identification & locations
Identify by its hardness (cannot be scratched by a steel knife), opaque nature, and smooth, waxy feel when wet. Often found in riverbeds or coastal rocky areas.
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Sandstone or Siltstone
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Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
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